The Natural History of the Berkshires

The Berkshires are some of the oldest mountains in the world, dating back about 500 million years. The mountains began as sediments between ancient continent margins. Over time, these were metamorphosed by heat and pressure from sand and silt to schist and marble and other rock formations. These were uplifted, creating a massive mountain range comparable in size to the Himalayas. Over the millennia, weathering and heavy weathering during periods of glaciation carved these mountains in the lower lying peaks, giving it “the cozy, soft feel” of the mountains today, as Dale Abrams of Mass Audubon explains.

There is an impressive diversity in the wildlife to be found here in the Berkshires. You don’t often think about how the bedrock affects the diversity of life you find in the Berkshires, but the connection is distinct. There is a broad range in acidity of the metamorphic rocks from the more acidic quartzite to the more alkaline limestone and marbles, “and when there is a range in Ph, there is a range in the botany or plant life you find here. When you have a greater variety of plant life, you have a greater variety of animal and bird life.”

An additional factor contributing to the rich diversity is that the region sits on the border between biological zones you would find in the north woods of northern New England and Canada and zones you would find in the south. A perfect example of this is found on Mt. Greyock,

“where you can find a forest similar to a boreal forest with a spruce-fir composition that are isolated from the boreal forest and totally different animals like to be in that versus the southern edge where there are lots of hickory species.”

The last significant contributor to the rich diversity you find in the Berkshires is the unique hydrology of the region. We have a lot of upland areas and rich valley bottoms where there a lot of the limey soils are. “In those areas, we have incredible wetland complexes which are super rich for plant life. The hydrology here also makes for a huge diversity of amphibians here."

There are about two dozen species of amphibians in this county from salamanders to frogs and toads. That is truly remarkable. This ripples out to bird life as well.

lenox berkshires summer 2

What has made the Berkshires habitable for many species includes humans. For over ten thousand years, the region has been inhabited by Native Americans and for the last three hundred or so by Europeans. Throughout the woods of the Berkshires, you can find signs of old farms in the middle of the woods such as the common stone walls you see throughout the region.

“Since the Erie Canal opened up the Midwest and western states to agriculture, this region shrank in population and the forests rebounded on abandoned farms. With the return of forests with the last hundred and fifty years, all these species that were once wiped out from the region began to return. Beavers were gone from the fur trade. Turkeys were hunted out. Porcupines and fishers were all gone. When the forests returned all of these species made their way back into the newly rebounded habitat. The Berkshires tells a story of ecological recovery of pretty epic preportions."

Being a witness to this recovery is absolutely fascinating, Abrahms explains.

In this sanctuary (Pleasant Valley Wildlife Sanctuary), you can find tracks or sign of bobcat, coyote, fox— right outside my office. If you’re up on the ridge, you can find fisher, porcupine… virtually every species that was gone has returned. In about 1932, beavers were reintroduced to this area and started to populate the whole valley. They created this whole network of pools within what was once just a stream in the valley bottom.

With that, they created openings around these pools as they foraged for food and created deeper water which made space for fish. As a result great blue heron numbers are really good in here and wood duck and hooded merganser—two more rare species—plus kingfishers. You can see these kingfishers diving for fish and wood ducks diving underwater. There are also smaller songbird species that thrive in this beaver habitat as well such as various flycatcher species. The woodpeckers like it too with the dead stands that are created.

Housatonic Flats Berkshire Hikes

“Here in the Berkshires, you can climb through the various plant communities as you increase in elevation and you can see all kinds of different species, depending whether you are in the lower hemlocks or the mid-elevation oaks or the spruces up on Greylock. This is especially true with the warblers. Here by the beaver ponds, you find yellow warbler and the common yellow throat. As you go up, you are likely to find black throated greens, black throated blues.”

There’s never a dull moment hiking out here, because you can move through so many ecosystems in a short time and as a result, see a lot of different wildlife.

Nicholas Tuff is a white-water kayaker, avid hiker, environmental educator and outdoor enthusiast living in western Massachusetts. He also enjoys the folk traditions of the region in particular the contradancing and shape note singing traditions